Prevent Windows Update from Forcibly Rebooting Your Computer

@ 2007/10/15
We've all been at our computer when the Windows Update dialog pops up and tells us to reboot our computer. I've become convinced that this dialog has been designed to detect when we are most busy and only prompt us at that moment.

The real problem comes into play when Windows gets tired of reminding us and says that the computer is going to reboot in 5 minutes, and the only way you can prevent the inevitable is to temporarily disable Windows Update.

Comment from jmke @ 2007/10/16
I've read about a few nasty "updates" like these too; for example during our madmovie project, the PC was encoding the final movie, this takes a while, so we left the PC running and left the room. Few hours later we return and end up staring at the logon screen, the machine had rebooted, the encoding cancelled, the source file corrupt.. thanks Microsoft!
Comment from Kougar @ 2007/10/16
Thank you! This was my biggest pet peeve with XP SP2 until I discovered the GPEdit.msc could disable it... but that trick wouldn't work in Vista.